Surge protection for 4-20mA sensors and data logger?

[andrea@xxxxxxxxxxxxxxxx]

Hi all!

For my grandpa's country I am going to install tens of 4-20mA sensors,
which will be routed through some hundreds meters of good cable to the
data logger, at the border of the house. To give some (yes, I know it's
impossible to give total) protection against nearby lightings, etc.. I
thought about adding surge protection.

If I understand it right, I should put one device in parallel with each
sensor, and another device in parallel with each data logger input (i.e.
the two ends of each cable), right?

Varistors, gas-dischargers, etc.. to me it seems that a Transil diode may
be a very cheap solution but a very effective one nonetheless. Am I wrong?

And, being there two in parallel for each cable (one at the sensor and
the other at the data logger input), are they going to false the results
by much? I am aiming at 16bit resolution, with a full scale precision of
about 0.1%

Thank you!
Andrea